Solve for $x$ and $y$ using elimination. ${2x-4y = -36}$ ${-2x-5y = -54}$
We can eliminate $x$ by adding the equations together when the $x$ coefficients have opposite signs. Add the equations together. Notice that the terms $2x$ and $-2x$ cancel out. $-9y = -90$ $\dfrac{-9y}{{-9}} = \dfrac{-90}{{-9}}$ ${y = 10}$ Now that you know ${y = 10}$ , plug it back into $\thinspace {2x-4y = -36}\thinspace$ to find $x$ ${2x - 4}{(10)}{= -36}$ $2x-40 = -36$ $2x-40{+40} = -36{+40}$ $2x = 4$ $\dfrac{2x}{{2}} = \dfrac{4}{{2}}$ ${x = 2}$ You can also plug ${y = 10}$ into $\thinspace {-2x-5y = -54}\thinspace$ and get the same answer for $x$ : ${-2x - 5}{(10)}{= -54}$ ${x = 2}$